Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. A method, comprising: determining a respective signal graph of each of a plurality of wireless local area network (WLAN) access points (APs) in a positioning area, wherein each respective WLAN AP signal graph comprises coordinates of a respective plurality of reference points and a WLAN AP signal strength corresponding to coordinates of each reference point of the respective plurality of references points; estimating a WLAN AP location of a first WLAN AP based on a first WLAN AP signal graph corresponding to the first WLAN AP, to obtain an estimated WLAN AP location of the first WLAN AP; determining a divergence of the first WLAN AP signal graph based on the estimated WLAN AP location of the first WLAN AP; and determining, based on the divergence of the first WLAN AP signal graph, whether the first WLAN AP is a mobile WLAN AP.
This invention relates to wireless local area network (WLAN) positioning systems, specifically addressing the challenge of identifying mobile access points (APs) within a positioning area. The method involves analyzing signal strength data from multiple WLAN APs to detect movement, which is critical for accurate indoor positioning and location-based services. The process begins by generating a signal graph for each WLAN AP in the area. Each graph maps signal strength values to coordinates of reference points, creating a spatial representation of signal propagation. For a first WLAN AP, its location is estimated using its signal graph data. The system then evaluates the divergence of this signal graph by comparing the observed signal strengths to the expected values based on the estimated location. High divergence indicates inconsistency, suggesting the AP may be mobile. By analyzing this divergence, the method determines whether the first WLAN AP is stationary or mobile. This approach improves positioning accuracy by filtering out unreliable signals from moving APs, which can distort location estimates. The technique is particularly useful in dynamic environments where APs may be temporarily relocated or carried by users. The method relies on signal strength patterns and spatial analysis to distinguish between fixed and mobile APs, enhancing the reliability of WLAN-based positioning systems.
2. The method according to claim 1 , wherein estimating the WLAN AP location of the first WLAN AP based on the first WLAN AP signal graph comprises: dividing a signal strength change range in the first WLAN AP signal graph into a plurality of signal strength change intervals; and separately estimating, based on coordinates of reference points corresponding to the plurality of signal strength change intervals, a plurality of WLAN AP locations corresponding to the plurality of signal strength change intervals, to obtain a plurality of separately estimated WLAN AP locations corresponding to the plurality of signal strength change intervals.
This invention relates to wireless local area network (WLAN) access point (AP) location estimation, addressing the challenge of accurately determining AP positions in environments where signal strength data is available but precise location information is lacking. The method improves upon traditional techniques by analyzing signal strength variations to refine AP location estimates. The process involves generating a signal graph for a WLAN AP, which plots signal strength changes over time or space. The signal strength change range within this graph is divided into multiple intervals, each representing distinct signal behavior patterns. For each interval, reference points—such as known locations or anchor points—are used to estimate the AP's position. By processing multiple intervals separately, the method produces a set of estimated AP locations, each corresponding to a specific signal strength change interval. This approach enhances accuracy by accounting for variations in signal propagation and environmental factors that affect signal strength. The technique is particularly useful in scenarios where initial AP locations are uncertain or where signal strength data is noisy. By leveraging multiple signal strength intervals and their associated reference points, the method provides a more robust and precise estimation of the AP's true location compared to single-point or average-based approaches. This can improve network planning, troubleshooting, and optimization in both indoor and outdoor WLAN deployments.
3. The method according to claim 2 , wherein determining the divergence of the first WLAN AP signal graph based on the estimated WLAN AP location of the first WLAN AP comprises: determining, based on the plurality of separately estimated WLAN AP locations corresponding to the plurality of signal strength change intervals, a plurality of divergences respectively corresponding to the plurality of signal strength change intervals.
4. The method according to claim 3 , wherein determining, based on the divergence of the first WLAN AP signal graph, whether the first WLAN AP is a mobile WLAN AP comprises: when smaller endpoint values of a signal strength change interval of the plurality of signal strength change intervals indicate a larger divergence corresponding to the signal strength change interval, or when larger endpoint values of a signal strength change interval of the plurality of signal strength change intervals indicate a smaller divergence corresponding to the signal strength change interval, determining that the first WLAN AP is a mobile WLAN AP.
5. The method according to claim 1 , wherein estimating the WLAN AP location of the first WLAN AP based on the first WLAN AP signal graph comprises: obtaining, based on the first WLAN AP signal graph, coordinates of each reference point corresponding to the first WLAN AP, and estimating the WLAN AP location of the first WLAN AP using a weighting algorithm, wherein a weight of the weighting algorithm is determined by a signal strength of a corresponding reference point.
6. The method according to claim 1 , wherein estimating the WLAN AP location of the first WLAN AP based on the first WLAN AP signal graph comprises: calculating L * = ∑ i = 1 N w i L i based on the first WLAN AP signal graph, to obtain the WLAN AP location of the first WLAN AP, wherein L* is the estimated WLAN AP location of the first WLAN AP, L i is coordinates of an i th reference point in the first WLAN AP signal graph, w i is a weight corresponding to the coordinates of the i th reference point in the first WLAN AP signal graph, w i = 1 / R S S i ∑ N j = 1 1 / R S S j , i = 1 , 2 , … , N , RSS i represents a signal strength of the i th reference point in the first LAN AP signal graph, and RSS j represents a signal strength of a j th reference point in the first WLAN AP signal graph.
7. The method according to claim 1 , wherein determining the divergence of the first WLAN AP signal graph based on the estimated WLAN AP location of the first WLAN AP comprises: calculating an average value of Euclidean distances between the plurality of respective reference points in the first WLAN AP signal graph and the estimated WLAN AP location of the first WLAN AP, and determining the average value as the divergence of the first WLAN AP signal graph.
8. The method according to claim 1 , wherein determining the divergence of the first WLAN AP signal graph based on the estimated WLAN AP location of the first WLAN AP comprises: calculating d i v j = ∑ i = 1 N j ( L i ( x ) - L * ( x ) ) 2 + ( L i ( y ) - L * ( y ) ) 2 N j , wherein div j is the divergence of the first WLAN AP signal graph, L i (x) is a horizontal coordinate of an i th reference point in the first W WLAN AP signal graph, L i (y) is a vertical coordinate of the i th reference point in the first WLAN AP signal graph, L*(x) is a horizontal coordinate of the estimated WLAN AP location of the first WLAN AP, L*(y) is a vertical coordinate of the estimated WLAN AP location of the first WLAN AP, and N j is a quantity of reference points.
9. The method according to claim 1 , wherein before determining the respective signal graph of each of the plurality of WLAN APs in the positioning area, the method further comprises: obtaining a plurality of WLAN AP signal strength values of each reference point in the positioning area; and calculating a variance of the plurality of WLAN AP signal strength values; and wherein determining the respective signal graph of each of the plurality of WLAN APs in the positioning area comprises: when the variance is less than a variance threshold, determining the respective signal graph of each of the plurality of WLAN APs in the positioning area.
10. The method according to claim 1 , wherein determining, based on the divergence of the first WLAN AP signal graph, whether the first WLAN AP is a mobile WLAN AP comprises: when it is determined that the divergence is greater than an outdoor divergence threshold, determining that the first WLAN AP is a mobile WLAN AP.
11. A method, comprising: determining a respective signal graph of each of a plurality of wireless local area network (WLAN) access points (APs) in a positioning area, wherein each respective WLAN AP signal graph comprises coordinates of a respective plurality of reference points and a WLAN AP signal strength corresponding to coordinates of each reference point of the respective plurality of references points; estimating a WLAN AP location of a first WLAN AP based on a first WLAN AP signal graph corresponding to the first WLAN AP, to obtain an estimated WLAN AP location of the first WLAN AP; determining a divergence of the first WLAN AP signal graph based on the estimated WLAN AP location of the first WLAN AP; determining, based on the divergence of the first WLAN AP signal graph, whether the first WLAN AP is a mobile WLAN AP; when it is determined that the first WLAN AP is a mobile WLAN AP, deleting fingerprint data of the mobile WLAN AP from a fingerprint database; and matching a first signal strength in the positioning area with a signal strength of each reference point in the fingerprint database, to determine a positioning result of an apparatus corresponding to the first signal strength.
12. The method according to claim 11 , wherein estimating the WLAN AP location of the first WLAN AP based on the first WLAN AP signal graph comprises: dividing a signal strength change range in the first WLAN AP signal graph into a plurality of signal strength change intervals; and separately estimating, based on coordinates of reference points corresponding to the plurality of signal strength change intervals, a plurality of WLAN AP locations corresponding to the plurality of signal strength change intervals.
13. The method according to claim 12 , wherein determining the divergence of the first WLAN AP signal graph based on the estimated WLAN AP location of the first WLAN AP comprises: determining, based on the plurality of separately estimated WLAN AP locations corresponding to the plurality of signal strength change intervals, a plurality of divergences respectively corresponding to the plurality of signal strength change intervals.
14. The method according to claim 13 , wherein determining, based on the divergence of the first WLAN AP signal graph, whether the first WLAN AP is a mobile WLAN AP comprises: when smaller endpoint values of a signal strength change interval of the plurality of signal strength change intervals indicate a larger divergence corresponding to the signal strength change interval, or when larger endpoint values of a signal strength change interval of the plurality of signal strength change intervals indicate a smaller divergence corresponding to the signal strength change interval, determining that the first WLAN AP is a mobile WLAN AP.
This invention relates to wireless local area network (WLAN) access point (AP) mobility detection. The problem addressed is identifying whether a WLAN AP is mobile or stationary based on signal strength variations. Traditional methods struggle to accurately distinguish between mobile and stationary APs, leading to inefficiencies in network management and location-based services. The method analyzes signal strength changes over time to determine AP mobility. A signal strength change interval is defined as a period where signal strength varies between two endpoints. The method evaluates the relationship between endpoint values and divergence (a measure of signal strength variability) across multiple intervals. If smaller endpoint values correlate with larger divergence or larger endpoint values correlate with smaller divergence, the AP is classified as mobile. This indicates that the AP's movement affects signal strength patterns in a predictable manner, distinguishing it from stationary APs where signal strength changes are less correlated with endpoint values. The technique improves network monitoring and service reliability by accurately identifying mobile APs, which may require different management strategies than fixed APs.
15. The method according to claim 11 , wherein estimating the WLAN AP location of the first WLAN AP based on the first WLAN AP signal graph comprises: obtaining, based on the first WLAN AP signal graph, coordinates of each reference point corresponding to the first WLAN AP, and estimating the WLAN AP location of the first WLAN AP using a weighting algorithm, wherein a weight of the weighting algorithm is determined by a signal strength of a corresponding reference point.
16. The method according to claim 11 , wherein determining the divergence of the first WLAN AP signal graph based on the estimated WLAN AP location of the first WLAN AP comprises: calculating an average value of Euclidean distances between the plurality of respective reference points in the first WLAN AP signal graph and the estimated WLAN AP location of the first WLAN AP, and determining the average value as the divergence of the first WLAN AP signal graph.
This invention relates to wireless local area network (WLAN) access point (AP) localization and signal graph analysis. The problem addressed is accurately determining the position of WLAN APs and assessing the reliability of signal strength measurements used for localization. The method involves analyzing signal strength data from multiple reference points to create a signal graph for each AP, then evaluating how closely these graphs align with the estimated AP location. Specifically, the divergence of a WLAN AP signal graph is calculated by computing the average Euclidean distance between each reference point in the graph and the estimated AP location. This average distance serves as a quantitative measure of divergence, indicating how well the signal graph matches the expected location. The method helps improve localization accuracy by identifying discrepancies between measured signal data and estimated positions, allowing for refinement of AP placement or signal models. The approach is particularly useful in environments where precise AP positioning is critical, such as indoor mapping or asset tracking systems. The technique leverages geometric distance calculations to provide a straightforward yet effective assessment of signal graph reliability.
17. The method according to claim 11 , before determining the respective signal graph of each of the plurality of WLAN APs in the positioning area, the method further comprises: obtaining a plurality of WLAN AP signal strength values of each reference point in the positioning area; and calculating a variance of the plurality of WLAN AP signal strength values; and wherein determining the respective signal graph of each of the plurality of WLAN APs in the positioning area comprises: when the variance is less than a variance threshold, determining the respective signal graph of each of the plurality of WLAN APs in the positioning area.
18. The method according to claim 11 , wherein determining, based on the divergence of the first WLAN AP signal graph, whether the first WLAN AP is a mobile WLAN AP comprises: when the divergence is greater than an outdoor divergence threshold, determining that the first WLAN AP is a mobile WLAN AP.
19. The method according to claim 11 , wherein matching the first signal strength in the positioning area with a signal strength of each reference point in the fingerprint database, to determine a positioning result of an apparatus corresponding to the first signal strength, comprises: calculating a Euclidean distance according to the relation: d i = ∑ j = 1 M ( R S S I j - R S S i j ) 2 M , i = 1 , 2 , … , N , wherein RSSI j is a signal strength of a j th WLAN AP at an I th reference point in the positioning area, RSS i j is a signal strength of the j th WLAN AP at an i th reference point in the fingerprint database, N is a quantity of reference points in the fingerprint database, and M is a quantity of WLAN APs corresponding to the fingerprint database; and obtaining n shortest Euclidean distances from the Euclidean distance d i to obtain a positioning result L, wherein L = ∑ i = 1 n w i d i , w i = 1 / R S S i ∑ N j = 1 1 / R S S j , i = 1 , 2 , … , N , RSS i represents a signal strength of an i th reference point in the first WLAN AP signal graph, and RSS j represents a signal strength of a j th reference point in the first WLAN i AP signal graph.
20. A device, comprising: a non-transitory memory comprising instructions; and at least one processor coupled to the non-transitory memory, wherein when instructions are executed by the at least one processor, the instructions cause the device to: determine a respective signal graph of each of a plurality of wireless local area network (WLAN) access points (APS) in a positioning area, wherein each respective WLAN AP signal graph comprises coordinates of a respective plurality of reference points and a WLAN AP signal strength corresponding to coordinates of each reference point of the respective plurality of references points; estimate a WLAN AP location of a first WLAN AP based on a first WLAN AP signal graph, to obtain an estimated WLAN AP location of the first WLAN AP; determine a divergence of the first WLAN AP signal graph based on the estimated WLAN AP location; and determine, based on the divergence of the first WLAN AP signal graph, whether the first WLAN AP is a mobile WLAN AP.
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February 16, 2021
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